What age do they become independant?

Or what age would a mother duck stop brooding her ducklings? I have now successfully merged my lone duckling (male 4/5 weeks) with his 2 girlfriends ( 3 weeks) but he is still cheeping like crazzzy when i leave the room or am out of sight! please tell me this will stop one day soon?

Yes. He will. I had a lone duckling once and she would not stop chirping if I was out of sight. Then I guess she figured out I didnt care if she chirped or not lol. Just ignore him if he does that. He will get the idea.